The information processing system connected to the wide-area computer network generally adopts a form of utilizing the processing function of information processing apparatuses arranged in a central data center to transmit processing results to terminal devices. Particularly, in a utilization form of the information processing system named a cloud computing, processing is concentrated in the information processing apparatuses such as servers and storages in the data center and the user utilizes the information processing apparatus from the outside connected to the data center through the network generally. The information processing apparatuses are concentrated in the data center by the cloud computing to thereby make it possible to minimize the system construction cost and the running cost.
In the utilization form named the cloud computing, the user receives provision of a server and a storage from a dealer making hosting to operate an application program (named an application or AP) on the server and store data in the storage, so that the user utilizes the information processing function using the server and the storage from a remote place. In this manner, the forms that the application is operated and the data is stored in the storage to be utilized are named application hosting and data hosting, respectively.
In the cloud computing, since processing is concentrated in the information processing apparatus in the data center, the quality of responses to information processing requests (throughput and response time of transfer data) is reduced when the users of system are increased and the information processing requests are increased to the information processing apparatuses in the data center from a lot of terminals. In order to keep the quality of the responses to the requests, it is necessary to increase the connection lines. In a company that provides the information processing apparatuses in the data center, the increased cost for increasing the lines is a problem on operation of business. Particularly, in recent years, until now, the problem is not expanded due to conditions that the processing performance of the user's terminal is not high or the access speed to a wireless access network for connecting the user's terminal to a core network is slow, although the request to the quality for the processing time is enhanced, so that the problem of further increasing the connection lines (securing the line quality) arises.
Accordingly, data center provider or business companies which borrow facilities from the data center provider to be utilized in hosing business or in its own company deliver replications of application and data in the information processing apparatuses installed dispersedly in the wide-area network and take load distribution measures for reducing the utilization frequency of the information processing apparatuses in the central data center, so that the quality of responses to the information processing requests is kept. As one of such load distribution techniques, the contents delivery network (CDN) is given. The CDN technique is disclosed in Patent Literatures 1 and 2, for example.
Furthermore, Patent Literature 3 describes a system which can change an information processing position by using an intelligent node having information processing function and any address change function to provide an information processing system with small delay.